1. Field of the Disclosure
The present disclosure relates to a prepayment-type watt-hour meter, and more particularly to a prepayment-type watt-hour meter that recognizes a code image in which information on prepayment is stored and, based on the information on the prepayment, calculates an electric bill.
2. Background of the Disclosure
FIGS. 1A and 1B are a diagram illustrating an example of a prepayment-type watt-hour meter in the related art.
FIG. 2 is a flowchart illustrating a process that is performed by the prepayment-type watt-hour meter in the related art.
In preparation for a prepayment-type billing system, the prepayment-type watt-hour meter in the related art includes an input unit for inputting information on a charge-based amount of electric power. There are two types of input units: a keypad type (FIG. 1A) and a card sensing type (FIG. 1B). When, using the keypad, a user inputs a code that includes the information on the charge-based amount of electric power that is paid for, a calculation unit of the prepayment-type watt-hour meter in the related art, which performs the process illustrated in FIG. 2, detects a validity of such an input code. In a case where it is determined that the input code includes the information on the legitimate charge-based amount, the prepayment-type watt-hour meter in the related art adds the legitimate charge-based amount to an existing charged-based amount that is stored in the prepayment-type watt-hour meter, thereby allowing electric power to be consumed by as much as a sum of the legitimate charge-based amount and the existing charge-based amount. Then, a price for the charge-base amount of electric power that is not consumed is displayed on the display unit of the prepayment-type watt-hour meter. When the validity of the code being input is found erroneous, an input code error message is displayed on the display unit. In a case where the error occurs more than three times, a function of inputting the information on the charge-based amount using the keypad is suspended for a predetermined time. The input unit that is the card sensing type also receives the information on the charge-based amount of electric power from a card that comes into contact with the input unit, and reads the charge-based amount of electric power.
A problem with the keypad type in the related art is that an error is likely to occur when a code is lengthy or an old person inputs the code. Another problem is that when an input occurs repeatedly, a function of preventing an input is likely to be performed for a long period of time. A further problem is that in the case of the card sensing type is that there occur additional costs of manufacturing and selling the card, A still further problem is that some users think the use of the card inconvenient. A still further problem is that, in a case where a prepayment-type card for consuming electric power is issued to a poor senior citizen who lives alone in terms of welfare for the poor senior citizen, there is a likelihood that the card will be used for the unlawful purpose such as a copy of the code, a transfer of the code, and a lease of the code.